Sheet feeding machines



A ril 11, 1961 H. T. BACKHOUSE SHEET FEEDING MACHINES 5 Sheets-Sheet 1 Filed July 2, 1958 April 11, 1961 H. T. BACKHOUSE SHEET FEEDING MACHINES 3 Sheets-Sheet 2 Filed July 2, 1958 April 11, 1961 H. T. BACKHOUSE 2,979,331

SHEET FEEDING MACHINES 5 Sheets-Sheet 3 Filed July 2, 1958 United States Patfi o I 2,979,331 SHEET FEEDING MACHINES Headley Townsend Backhouse, Les Rayons,

Corsy-Conversion (V and), Switzerland The invention relates to sheet feeding machines of the kind in which sheets of paper, card, thin metal or the like are fed in succession (e.g. as a continuous stream of partly overlapping sheets) over a feed table to a front lay station where each sheet in turn is arrested with its front edge against front lays in order to obtain accurate registration of the sheet and in which the movement of each sheet is slowed down as'the sheet approaches the lay station by a slow down device which engages the front'edge of the sheet and travels with the sheet at a constant or decreasing speed which is, or the average of which is, less than'that at which the sheets are fed over the table.

According to the invention a machine of the above kind is characterised by the features that the slow down device is carried by an endless chain, band or like flexible element constrained for movement beneath the table around an endless path with upper and lower oppositely moving laps extending in the direction of travel of the sheets, and means are provided for moving the flexible element in the direction such that the upper lap travels in the same direction as the sheets, the slow down device projecting upwardly above the table when travelling along the upper lap and being withdrawn below the top of the table when travelling along the lower lap.

There may be several slow down devices carried by the element for engagement with successive sheets respectively.

In one form of the invention the slow down device (or each device) is in the form of a hook which, when travelling along the upper lap, faces upstream for reception of the edge ofa sheet. In another form or a modification of that just referred to, the slow down device is constructed as a gripper which closes onto the edge of the sheet.

The machine may include means for first raising the slow down device above the feed table and then lowering the device, as the device travels along the feed table. Alternatively the chain or the like may be constrained to move downwardly over the first part of the upper lap so that the slow down device, or part thereof (eg the upper limb of a hook) moves downwardly during the first of its travel along the table and then moves parallel to the table.

When the slow down device is to travel at a variable speed the chain, band or the like may be driven by an eccentric gear, rotating once for each sheet.

A specific construction of a sheet feeding machine according to the invention will now be described by way of example, and with reference to the accompanying drawings in which:

Figure 1 is a diagrammatic plan view of one side of the feed table and associated parts,

Figure 2 is a side view of one of the slow down units of the machine, one half of the casing having been removed to show the internal parts.

Figure 3 is a section on the line 3-3 in Figure 2,

. 2,979,331 Patented Apr. 11, 1961 ice Figure 4 is a plan view of the unit, and

Figure 5 is a diagrammatic side view showing a modified construction of the slow down unit.

The machine forming the subject of this example has a feed table 10 over which sheets are fed from a conveyor, as a continuous stream, to front lays 11 which are constructed and arranged for operation as disclosed inmy specification Serial No. 746,136, of even date, now US. Letters Patent 2,950,916.

The feed table is constructed in sections 10a, 10b, 10c, 10d and 10e. 14, 15, and 16 secured at their ends in side frames 17. The centre section 10d is fixed to the cross-bars, whereas sections 10a and 10b are readily removable. The remaining sections (i.e. 10c and 10e) are slidable along the bars between different positions of adjustment. Ac cordingly the effective width of the table and the number and separation of the front lays 11, may be varied. The section 10e carries side lay mechanism indicated diagrammatically at 18, the details of this mechanism forming no part of the present invention.

The sections 10c of which there are two (iLe. one on each side of the table) carry the slow down devices for slowing down the movement of the sheets before they contact the front lays 10. .The two devices are alike and only one will be described.

The section is constructed of two castings 20, 21

bolted together, the construction providing an internal cavity 22 with a slot 23 in the top face of the section. The castings have forks 25, 26 which engage the bars 14, 15 and a bore 27 which receives the bar 16. A locking screw 29 serves to secure the section at various positions along the bars.

At the bottom of the cavity there is a gear wheel 30 keyed to a driving shaft 31, the shaft being supported on the side frames 17 and rotated continuously during the operation of the machine. The gear wheel is slidable along the shaft. The gear 30 meshes with a gear 32 to which is attached a chain sprocket 33 and a cam 34. A chain 35 connects the sprocket 33 with a driven sprocket 36, A sprocket 38 is integral with sprocket 36 and is connected by an endless chain 39 to a sprocket 40.

The chain 39 carries three equally spaced slow down hooks 41 which project upwardly through the slot 23 as the chain moves along its upper lap. The books, as.

Engaging. the underside of the upper lap of chain 39,

there is a roller 44 which is carried on one arm 45 of a bell-crank lever, the other arm 46, having a roller 47 which runs on the cam 34 so that the cam rocks the lever to effect up and down movements of the roller 44 and the upper lap of the chain. The up and down movements are effected in such timed relation that the hooks follow the path indicated by arrows in Figure 2, the hooks moving upwardly, in turn, in time to receive a sheet while in raised position. It will be seen that the hooks rise gradually from a position below the top of the table at the beginning of their travel along the upper lap.

In order to accommodate the changes in tension of the chain 39 due to the movements of roller 44, the sprocket 38 is carried on a spindle 50 which is cccentrically mounted on pivot pins 51 in the castings 20, 21. A spring 52 acting on a pin 53 secured to spindle 50 serves to maintain the tension in the chain.

Figure 5 shows a modification of the above construc-' The sections are supported on cross-bars hooks, i.e. the hooks slow down as they travel to the left while holding a sheet, from a speed more than half the initial speed of the sheets to less than half that speed. In this modification there is an eccentric gear 55 on shaft 31 which drives a gear 56 coupled to the lower sprocket 33a of the driving chain 35. The gear 56 and sprocket 33a are carried on a frame pivoted about the axis of sprocket and a spring 57 acting on the frame maintains the gears 55 and 56 in engagement. The speed variation is preferably about 40 to 50%.

I claim:

1. In a sheet feeding machine comprising a feed table over which sheets are fed in succession to a front lay station where each sheet in turn is arrested with its front edge against front lays in order to obtain accurate registration of the sheet, means for slowing down each sheet as the sheet approaches the front lay station which means comprise an endless flexible element, means for constraining the element around an endless path in an upright plane beneath the table, the path having upper and lower laps extending in the direction of travel of the sheets, means for moving the flexible element around the path in the direction such that the upper lap travels in the same direction as the sheets, the lower lap travelling in the opposite direction, a slow down device attached to the element for movement therewith, the slow down device projecting outwardly from the path and upwardly above the top of the table when travelling along the upper lap for engagement with the front edge of a sheet approaching the front lay station, and the slow down device being withdrawn below the top of the table when travelling along the lower lap, and means for producing a hump in the upper lap at a position intermediate in the length thereof whereby as the slow down device travels along the upper lap it is first raised relative to the table and then lowered.

2. A sheet feeding machine as claimed in claim 1 in which the means aforesaid for producing a hump in the upper lap comprises a support member engaging the upper lap at a position intermediate in the length thereof, and means for imparting up and down movement to the support member in such timed relation with the travel along the upper lap of the slow down device that as the slow down device approaches the said position the support member is raised to form a hump and immediately after the slow down device has passed the said position the support member is lowered.

References Cited in the file of this patent UNITED STATES PATENTS 847,379 Smiley Mar. 19, 1907 935,496 Hanan Sept. 28, 1909 1,421,569 Ritchie et a1. July 4, 1922 1,545,914 Maxson July 14, 1925 2,039,785 Eckhard May 5, 1936 2,170,489 Spiess Aug. 22, 1939 2,201,539 Kast May 21, 1940 2,605,103 Backhouse July 29, 1952 2,613,930 Backhouse Oct. 14, 1952 2,848,226 Buttner et a1 Aug. 19, 1958 

